Preliminary optimization of the PCCI combustion mode in a diesel engine through a design of experiments

A premixed-charged compression ignition (PCCI) combustion mode has been applied to a Euro VI heavy-duty production engine to simultaneously diminish particulate matter and nitrogen oxide exhaust emissions. The considered methodology exploits statistical techniques to efficiently plan tests, analyze acquired data and provide cause-and-effect relationships about the observed phenomena. Regression models were designed to predict the desired outputs as functions of selected inputs. The model-based optimal calibration of the PCCI combustion led to a reduction of up to 90% in NOx and 99% in soot emissions, along with a fuel penalty of 9-13%, and an excessive increase in HC and CO. (C) 2016 The Authors. Published by Elsevier Ltd.